Armor structures, such as ceramic plates used in body armor and other high-strength structures, are the subject of ongoing improvement efforts. More specifically, many pieces of modern body armor are composite structures. A major layer of the structure is the ceramic plate, which plays a decisive role in armor performance. The ceramic plate can be damaged by impact and this damage will affect subsequent armor performance. Detection of the damage is therefore very important. Accordingly, much current effort is focused on the reliable detection of damage in armor structures. Damage detection of armor structures is very important for the safety of protected people, vehicles or facilities. Maintaining the protection integrity of armor is vital to protection of life.
A major conventional damage detection method for inspecting armor employs X-ray imaging and visual inspection of the images. This method is generally inconvenient and of limited usefulness in the field. This damage detection procedure also requires well-trained personnel to inspect the images and precautions for radiation shielding. Thus, the cost of deploying such an inspection method is relatively high. Therefore, it is desirable to develop a method that is easy to use, does not adversely impact the weight or strength of the armor, and has a lower cost as compared to X-ray methods. It is further desirable to develop reliable armor damage detection methods that can be used in field conditions.